How the Test is Performed

Clean-catch urine sample

How to Prepare for the Test

No special preparation is needed.

How the Test Will Feel

The test involves only normal urination.

Why the Test is Performed

This test is used to diagnose melanoma, a type of skin cancer that produces melanin. If the cancer spreads (especially within the liver), the cancer may produce enough of this substance that it shows up in the urine.

Normal Results

Normally, melanin is not present in urine.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

Urine sample - illustration

A "clean-catch" urine sample is performed by collecting the sample of urine in midstream. Men or boys should wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well. A small amount of urine should initially fall into the toilet bowl before it is collected (this clears the urethra of contaminants). Then, in a clean container, catch about 1 to 2 ounces of urine and remove the container from the urine stream. The container is then given to the health care provider.

Urine sample

illustration

Urine sample - illustration

A "clean-catch" urine sample is performed by collecting the sample of urine in midstream. Men or boys should wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well. A small amount of urine should initially fall into the toilet bowl before it is collected (this clears the urethra of contaminants). Then, in a clean container, catch about 1 to 2 ounces of urine and remove the container from the urine stream. The container is then given to the health care provider.